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Newsletter

DIPOL Weekly Review - TV and SAT TV, CCTV, WLAN

No. 13/2009 (March 30, 2009)

Will femtocells accelerate the development of wireless technologies? Femtocells are access points operating in mobile telephony standard (mainly UMTS these days), which are connected to broadband Internet (via xDSL or FTTH). Unlike GSM amplifiers/repeaters that amplify radio signals coming from operators' cellular infrastructure, they connect to the networks of the operators via other broadband services and broadcast their radio signals as separate base stations (BTS). Femtocells have been developed in order to relieve the existing cellular base stations and increase the coverage of mobile networks in homes and small businesses. Their use will allow, among other things, to reduce the cost of building infrastructure for mobile networks using new standards, such as LTE. Last year, 3GPP organization (Third Generation Partnership Project) reported a preliminary agreement on the protocol referred to as "Iu-h". It defines the way in which femtocells set up connections between the Internet and 3G networks.

Use of femtocell

Key features of femtocells:

low power transmission - adequate to cover small areas and not influencing the existing infrastructure of the operators (interferences),

improvement of transmission quality from cellular phones.

Femtocells are perfectly suitable for homes, offices and other places with access to xDSL or FFTH links.

They allow to reduce prices for multimedia connections.

Today many manufacturers of telecommunications equipment introduce devices that can work as femtocells. These devices are able not only to perform this role, but also combine many different functions such as ADSL2 +, Wi-Fi, VoIP and full support for 3G networks.

At CeBIT, Netgear company presented its latest device combining features of femtocell, access point, VoIP gateway, and switch. These functions enable the users to get Wi-Fi and VoIP connections, connect their computers to the Internet etc. The manufacturer has implemented SPI double firewall and support for 3G technology.

CeBIT - NETGEAR about femtocells

Intertelecom 2009 - the crisis has been heard but not seen. The concerns regarding the current state of the economy in Eastern Europe can be confronted with the real situation reflected by the trade fair that took place in Poland, providing data for analysis of the Polish telecommunications market. Intertelecom 2009 was held in Lodz from March 17 to 19. This International Fair of Electronic Communication drew a 100 or so companies - it represented a 25 percent decline from last year. The slump is like in the case of the global events like CeBIT, the characteristics of the companies that withdrew from the fairs have much in common as well. The absentees were mostly large international companies, including integrators and manufacturers. Lack of Polish cable manufactures, well known in the world, was a sign of problems in the market caused by investment cuts. Well represented group of small and medium-sized companies exhibited products in the fields of wireless communications, satellite TV and IPTV, as well as video surveillance (CCTV). In addition, discussions with representatives of these companies revealed that they do not see visible signs of a crisis. There were neither differences in sales nor problems with payments. However, it is important to note that the WLAN, satellite TV, CCTV industries are mainly based on the consumer segment that has not yet experienced economic problems. Unfortunately, the entrepreneurs running these businesses expect that some difficulties may arise at the end of this year.

Where is this tower? The construction of the tower visible in the photo below was undertaken in 2005. It should be ready in 2010, reaching 610 meters. The tower will become the second highest building in the world, just after the 818 meters high Burj Dubai, officially opened on January 17, 2009. In addition to television and radio transmitters, the tower will house many restaurants and cinemas. The biggest attractions will be the garden located at the height of 450 meters and the staircase on the outer wall of the building, to the height of 370 meters - up to the rotating restaurant with observation deck. Do you know where the tower is being built? Anyway, the answer you can find at the end of this issue.

In 2010 it will be the highest TV tower in the world. Where is the tower being built? The answer you can find at the end of this issue. (Source: Wikipedia)

MMH-3000 headend - transmission range up to 30 km. Transmission of RF signals in SMATV/MATV and cable TV systems based on coaxial cables is limited to distances of about 500 meters from the headend (within the circular area of that radius). The reason is the attenuation of the cables. When there is a need of transmitting the signals over a longer distance, the solution is an optical transmission line. We offer TERRA devices for the popular MMH-3000 headend, allowing to build optical links based on single-mode optical fiber (SMF). An SMF with typical attenuation rate of 0.34 dB/km, the basic optical transmitter MOS-211A R81720 (optical power 6 dBm), and optical node OD-200P R81722 (minimum optical input level -7 dBm), allow to build a 30 km optical link (a reserve of ca. 3 dBm).

Available models (to order) include devices with higher optical power:

Name

MOS-211A

MOS-211B

MOS-211C

MOS-211D

MOS-211E

MOS-211F

MOS-211G

Optical power

6 dBm

7 dBm

8 dBm

9 dBm

10 dBm

11 dBm

12 dBm

Megapixel lenses. One-megapixel camera (1 Mpx - 1,000,000 pixels) provides over twice the pixels than standard PAL camera (704 x 576 = 405 504 pixels). 5 Mpx cameras offer resolution of 2592 x 1944 pixels (12.5 times more pixels than PAL and 2.5 times more than HDTV images). So high resolutions of the sensors require using adequate lenses. Low-quality lenses would spoil the resultant images. For megapixel cameras there are used specially marked "megapixel" lenses. These high quality lenses exhibit substantially reduced geometric distortions and lower deformation of light waves passing through their optical lenses. The deformation is described by MTF parameter - Modulation Transfer Function. This parameter is essential for sharpness of the images, deciding on the identification capability of megapixel CCTV systems. Choosing a lens one has to take into consideration its exact specification for the specific group of megapixel cameras (e.g. up to 2Mpix etc). It is also important that the lenses should have set screws that block the zoom and focus rings. Similarly to other precision devices, the pitch of the thread should be fine enough to allow precise adjustment of the parameters, especially focus (inadequate precision could put the focus "out of tune" just by screwing down the set screws).

CCTV transmission via the Internet - summary - part 3/3. As we mentioned before, upload of images from multiple cameras to multiple users simply multiplies the width of the required band. In order not to exceed the throughput of the link, one can specify the maximum number of users that can simultaneously view the images from the cameras. One can also limit periods of connections with the source signals. These restrictions can be enforced on the Web server hosting the dynamic web page with the embedded images from the cameras.

For presenting the images to multiple users one should run Media Server

Providing the images to several users, one can utilize NVR server (ULTISYSTEM, NUUO). The user equipped with free client software or simply using Internet browser can connect to the NVR server. Depending on the way of displaying the images in the client program, the NVR server will maintain adequate stream, preserving normal operation of the network link.

The server built into the device recording images from the cameras is sufficient in the case of one or several users viewing live images or browsing the archives.

To sum up: To share online viewing of live surveillance video, the administrator first has to define the number of available cameras and the number of users who can simultaneously view the images, then he/she should select the best method.

Intelligent image analysis software allows to search the recordings on the basis of: motion detection, object disappearance, new object, loss of focus, tampering. The recorders can send e-mail messages - triggered by motion detection, signal loss or external alarm circuit. Due to Linux OS, they provide superior security, ensuring stable operation and resistance to computer viruses. NUUO K4104 and K4108 NVRs enable management of IP CCTV system and recording of the images from IP cameras. This allows to deploy video surveillance systems with remotely located cameras.

Please note that a single NUUO NVR has limited computing power, expressed by maximum bandwidth occupied by all cameras in the system. For 8-channel K4108 the maximum bandwidth is 30 Mbps, which provides 3.75 Mbps for each connected camera. However, the system can employ more than one recorder, and the operator has access to each channel and each archive. The interface enables the user to check how the NUUO NVR communicates with cameras, frame rate of each camera, and the total bandwidth. In the event the aggregate load exceeds the limit, the NVR displays appropriate information, which allows to prevent unstable operation of the system.

Unlike analog systems using PAL/NTSC standards, IP CCTV systems have to be carefully designed. It is important to select compatible devices that support the same compressions, transmission parameters and protocols, control signals etc.NVR NUUO - the list of compatible cameras.

Cable and LAN testers. The testers help installers to build LAN systems and service existing networks. They allow to tests cable continuity, detect shorts circuits and incorrect connections. Depending on the model, the devices can be used for UTP/FTP cables terminated with RJ-45/RJ-11 connectors or for 50 ohm coaxial cables terminated with BNC plugs.

ULTIAIR - efficient and secure wireless data transmission. One of the priorities of video surveillance systems is security of transmission. ULTIAIR devices have been carefully engineered to satisfy most professional requirements in this field. The implemented MikroTik operating system allows to use the currently safest WPA2-PSK protocol. It was one of the reasons why the authorities of Tvrdosin (Slovakia) decided to build city monitoring system based on this professional WLAN equipment. The system currently includes 8 megapixel cameras (2 Mpix), the video streams from 5 cameras are transmitted wirelessly.

How to protect the network based on ULTIAIR devices? First, one has to deploy point-to-point or point-to-multipoint links, then to create (for each device) New Security Profile:

log on to the device using WinBox utility,

select Wireless tab,

in the new window choose Security Profiles tab and click on + sign,

in the new window tick only WPA2 protocol,

in the WPA2 Pre-Shared Key field enter the password,

click on Apply and then OK.

New Security Profile

select Interfaces tab and double-click on wlan1,

in the new window choose Wireless tab and select as Security profile the previously created profile1,

Canton (Guangzhou). Guangzhou TV &Sightseeing Tower is being built in Guangzhou - the capital of Guangdong (Kwangtung / Canton) province in the southern part of China with about 14.5 million inhabitants. The first known city built at the site of Guangzhou was Panyu, founded in 214 BC. The first Europeans who arrived to the city by sea were Portuguese, establishing a monopoly on the external trade out of its harbor by 1511. Since the beginning of the 18th century it was the main hub of trade with the West. Now Guangzhou is the economic center of the Pearl River Delta, one of mainland China's leading commercial and manufacturing regions. In 2010 the region will host Asian Games, also called the Asiad. The opening of the tower is associated with this event.

We have written about:

Safe cables. Safety regulations for public buildings that house many people (hospitals, schools, theaters) require that during a fire the cabling cannot pose an additional threat to the life or health of the people. The cables have to be halogen free (HF) - they cannot give off toxic gases. When burned, the cables also cannot feed the fire, emit thick or corrosive fumes... - archive DWR of March 2, 2009

How to choose a mount for the LCD television? The MIS (Mounting Interface Standard) or FDMI (Flat Display Mounting Interface) standards of installation of flat panels (LCD/plasma monitors and televisions) has been developed by VESA (Video Electronics Standards Association).... - archive DWR of Jan. 14, 2008